Projecting-machine.



r.. ARMAL FROJECTLN'G MAGHINE.

APPLICATION FILED JULY 22' 1916.

1,259,067, Paten@ Mar. 12, 1918.

2 SHEETS-SHEET l.

Patented l. .12,1918.

2 SHEETS-SHEET 2.

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Il@ TNT FIQE.,

THOMAS BMAT, 0F 'WSHINGTOIL DISTRICT 0F COLUMBIA.

PBOJECTING-HACHINE.

Specication of Letters Patent.

Patenten Mar. ae, raie.

Application med-July 22, 1918. Serial No. 110,684.

To all lwhom t may concern.'

Be it known that I, THOMAS ARMAT, a citizen of the United States, residing at Washington, in the District of Columbia, have invented certain newv and useful Improvements in Projecting-Machines; and I do hereby declare the following to be a full, clear, and exact description of the same, reference being had to the accompanying drawings, forming part of this specification.

This invention relates to heat absorbing means, especially adapted to motion picture and other projecting apparatus where a beam of light is projected through 'an iniammable screen.

The primary object of the invention is to j absorb the heat rays from the light without appreciably aifecting the light rays.

' By the present invention, they necessity for ire shutters and other fire protection in motion picture apparatus is removed. It obviates the necessity for long title runners. Its advantages in microscopic j work will readily suggest themselves. By the employment of this improvement in motion picture projection, the film may be held at rest in the focus of the light as long as may be desired, so that any picture ma amined on the screen at leisure, wit out the least danger of setting fire to the hn. The present practice with title or announcement runners is to run them through the machine at the rate of about a foot a second, so that an announcement that would have to be given hali:l a minute to be read would be about thirty feet long, whereas, by employing my improvement, it need not be longer than a foot 0r two, and it could then be held on the screen not merely half a minute, but as much longer as could possible be desired.

A full understanding of the invention will be attained from the ensuing detailed description when taken in connection with the accompanying drawings which illustrate a structural embodiment of the inventionin a preferred form. The novel features will be pointed out in the claims at the end of the specication.

In the drawings Figure 1 is a side elevation partly in sec,- tion of a projecting apparatus embodying th? present impirovemntfs. 1

i 2 is a etaile ra entary ongitudiril section of the forwgamrd end of the lamp receptacle.

be cx-A which were condensed on an ordinar -third of a cubic foot surroundin Fig. 3 is a longitudinal section ofa lamp receptacle of a modified type. l

lFig. 4 is a transverse section of the device illustrated in Fi 3.

Like characters o reference 'in the sevl eral figures indicate the same parts.

Briefly stated, the principle underlying my invention and which is embodied in the devices illustrated in all the figures, is to absorb the heat rays, at the source, so to speak; in projection work before the heat reaches the condensers. I have found'that it is possible to do this by interposing a comparatively thin wall of water or other heat absorbing media, between the light and the condensers, provided the wall of water is connected with a larger body so that the heat it absorbs ma in turn be absorbed and carried away y the larger body of water, or other medium, with which it is connected. A

For the above purpose I interpose in the line of projection behind the condensin lens and between the lens and the source o light a body of heat absorbing liquid, such as water, which is preferably in direct communication with a body of similar liquid surrounding or substantially surrounding the source of light. By actual experiment I have found that a twenty-five ampere arc lamp inclosed in a water jacketed lamp house, as illustrated at'Fig. 3, the rays from moving picture lm for halfan hour, ad no appreciable heating efect on the ilm and it raised the temperature of less than a house only to degrees at the ottom and 110 degrees at the top. Had the light from this lamp been used in the way it has heretofore been universally employed 1t would have set fire to the ilm in a few seconds,

While itwill be obvious that many dilierent arrangements may be devised for carry-v .the lamp.

outer rin bodies, as will be understood, the usual projecting lenses, framing device, and means In front of the opening B', an open cylindrical cap b is secured to the outer wall of the casing. This cap is provided with'an inwardly extending annular flange b2 against which issupported a rubber or other water tight ring b3. Between said rin b3 and an outer ring b4 of similar materia is located a glasswindow B2 which covers the light j A metal ring b5 rests against the outer rubber ring b4 and the three rings and the glass window are clamped in position by a second cylindrical ca B3 whlch extends .within the ca b and 1s provided with an annular shoul er be resting; against b5. The mount D containing the rear con ensing lens Z is supported within the cap B3. The front condensing lens d is located within a mount D supported on the v rear of the projecting apparatus A.

Mounted on the top of the lamp casing B is a lamp mount E adapted to be adjusted thereon by a'screw e. This mount is provided with a. vertically extending bore for the reception of a water tight tube E', the latter projecting above the top of the mount E and surrounded by a cap E2 mounted on the top of the mount. A screw e2 in the cap E2 permits upward and lowering'movement of the tube E relatively to the mount. Supported at the lower end of the tube is an incandescent lamp L, the circuit wires of which extend upwardly through the tube, as indi cated by the cable Z. Preferably, the lamp L is located directl behind the light opening B and quite c ose up tothe dow B2,l as shown more particular y in Fig. 2. The position of the lamp L may be a justed as desired by manipulating the screws e, e2 and moving the mount E and the tube E up and down in the block. It is essential that the base of the lamp be protected from the water by a. water tight tube extending above the water level.

Extending into the casing or tank is a funnel F having an elongated spout f, which may be provlded with a short hose connection for use when running water is employed. The casing may beilled with water throu h said funnel, and water is poured in until it completely submerges the bulb of the lamp L. The water-extends aroundin front of the lamp and up against the glass plate B. leakage being prevented by the the outer chamber is a condensin glass winrubber rings on each side of the glass. Preferably, the water is circulated 1n the tank, and this is effected by placing in the tank a baie plate F. A cock F? permits the water to bedrawn off, as desired.

l/Vith the above construction, the beam of light must pass thrgugh the water and next the glass plate before it reaches the condenser lens. This, asbefore stated, has the eect of absorbing or extracting ractically all of the heat rays from the 11g t'without..

affecting appreciably its illuminating power. The absorption of heat is enhanced by reason of the factthat the lamp is entirely surrounded by water. When the light reachesthe film its heating power vis so reduced that the film may remain stationary in it indefinitely without catching fire.

"In the form shown in Figs. 3 and 4, the light receptacle placed behind the projecting apparatus is constructed for use with arc lamps. This receptacle embodies an outer chamber H andan inner chamber H. The outer 'chamber is provided in its front wall with alight opening h in the line of projection and the inner chamber with analined light openin Mounted in t e outside of the front wall of lens I. The inner member z" of the lens is held irm by a cap is against a rubber ring i, which in turn seats on a ange 2 carried by a c linder 5 rojecting from the front wall of t e outer c amber. This construction renders the outer chamber water tight. In front of the condenser lens is mounted a light cone I. Projecting from the front wall of the inner chamber and surrounding the light opening h is a cylindrical member lc into which is screwed a cylindrical cap K. A flanged ring K is seated in the opening h and the cap K holds against said ring Ic a glass window K located between rubber rings k2, k3.

The arc lamp apparatus M is mounted on the inner chamber H', the walls of said chamber being preferably provided with an insulating lining k2 to prevent short-circuiting of the current. Y

To permit ready access to the lamp M the inner chamber is provided with rearward and sidewise extensions H, Ha intersecting the walls of the outer chamber. Said inner chamber isv also provided with a chimney h also in its front wall.

sides ofthe inner chamber are substantially surrounded -by water and the water comletely fills the space between the condenser ens and the glass window in the inner chamber. The light rays from the arc lamp pass first through the glass window and then through the water, before they `reach the lens. A cock N permits the water to be drawn 0H as desired. It will be obvious that a circulation may be maintained by keeping the top cock N 2 open and maintaining a continuous liow through the funnel.

I am aware that cells containing water, alum water, etc., have heretofore been employed as heat absorbers in projection work.

What is claimed is:

1. A projecting apparatus embodying a condensing lens, a source of light and a water chamber substantially surrounding said source of light and extending between the same and the condensing lens.

2. A projecting apparatus embodying a condensing lens, a receptacle for a liquid heat-absorbing medium located in rear of said lens, and a. chamber for a sourcey of light located within said receptacle, whereby the heat-absorbing medium is interposed between the chamber and the condensing lens, and said chamber is substantially surrounded by said medium.

3. A projecting apparatus embodying a condensing lens, a receptacle for a liquid heat absorbing medium located in rear of said lens, a chamber for a source of light located within and substantially surrounded by the receptacle whereby a body of heatabsorbing medium will Vbe interposed between the source of light, condensin and walls of the receptacle, a source o light, and means accessible from the exterior of the receptacle for adjusting rthe position of the source of light with respect to the condensing lens.

4. In a projecting apparatus, the combination of an incandescent electric lamp, condensing and projecting lenses, and means for surrounding the lamp with a liquid heat absorbing medium adapted to absorb the heat rays from the lamp before they reach the condensing lens.

5. In a projecting apparatus, the combination of projecting and condensing lenses, a water tank behind the condensing lens having a light opening in its front wall and in the line of projection, saidlight opening lens n being provided with a water tight glass window, a body of water in the tank and a lamp immersed in the body of water behind the light opening.

6. In a projecting apparatus, thecombinati-on of projecting and condensing lenses, a water tank behind the condensing lens having alight opening in its front wall and in the line of projection, said light opening being provided with a water tight glass window, means for circulating water in the tank, and a lamp immersed in the water behind the light opening.

7. In a. projecting apparatus, the combination with a source of light, projecting and condensing lenses, of means for maintaining a volume of heat absorbing liquid between the source of light and the condensing lens, said volume of liquid extending backwardly around the source of light whereby heat rays passing toward the condensing lens are absorbed and carried by conduction and convection into the surrounding volume of liquid for dissipation into the surrounding atmosphere.

8. In `a projecting apparatus, the'combination with a source of light, condensing l and projecting lenses, of a receptacle for heat absorbing liquid substantially surrounding and spaced from the source of light, whereby heat rays passing from the source of light toward the condensing lens are absorbed by the liquid medium and transferred by conduction and convection for dissipationin the surrounding atmosphere through the walls of the receptacle.

9. In a projecting apparatus, the combination with a condensing lens, a heat absorbing liquid receptacle located in rear of said lens, a source of light located within the receptacle and spaced from the condensing lens, whereby the heat absorbing liquid may circulate around the source of light and between the same and the condensing lens, and a baille plate for augmenting the circulation of the heat absorbing medium, whereby heat absorbed between the source of light and condensing lens will be carried away and dissipated.

THOMAS ARMAT. 

